Graphene enables scientists to gain new clarity in visualizing the quantum realm

Scientists from Princeton, the University of Leeds, the University of California and the National Institute for Material Science in Japan have used innovative techniques to visualize electrons in graphene, and found that strong interactions between electrons in high magnetic fields drive them to form unusual crystal-like structures similar to those first recognized for benzene molecules in the 1860s by chemist August Kekulé.

Scientists visualize electron crystals in a quantum superposition image

These crystals exhibit a spatial periodicity that corresponds to electrons being in a quantum superposition. The experiments also showed the Kekulé quantum crystals have defects that have no analog to those of ordinary crystals made up of atoms. These findings shed light on the complex quantum phases electrons can form because of their interaction, which underlies a wide range of phenomena in many materials.

Researchers detect abnormally strong absorption of light in magnetized graphene

Researchers from Germany's University of Regensburg, Russia's MIPT, and U.S-based University of Kansas and MIT have discovered an abnormally strong absorption of light in magnetized graphene. The effect appears upon the conversion of normal electromagnetic waves into ultra-slow surface waves running along graphene. The phenomenon could help develop new ultra-compact signal receivers with high absorption efficiency for future telecommunications.

Magnetized graphene displays abnormal light absorption image

Everyday experience teaches us that the efficiency of light energy harvesting is proportional to the absorber area, as indicated by solar panel "farms" covering large areas. But can an object absorb radiation from an area larger than itself? It appears that way, and it is possible when the frequency of light is in resonance with the movement of electrons in the absorber. In this case, the area of radiation absorption is on the order of the light wavelength squared, although the absorber itself can be extremely small.

Researchers stabilize the edges of graphene nanoribbons and measure their magnetic properties

Researchers at Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley have developed a method to stabilize the edges of graphene nanoribbons and directly measure their unique magnetic properties.

The team, co-led by Felix Fischer and Steven Louie from Berkeley Lab’s Materials Sciences Division, found that by substituting some of the carbon atoms along the ribbon’s zigzag edges with nitrogen atoms, they could discretely tune the local electronic structure without disrupting the magnetic properties. This subtle structural change further enabled the development of a scanning probe microscopy technique for measuring the material’s local magnetism at the atomic scale.

Researchers take a step towards achieving topological qubits in graphene

Researchers from Spain, Finland and France have demonstrated that magnetism and superconductivity can coexist in graphene, opening a path towards graphene-based topological qubits.

Schematic illustration of the interplay of magnetism and superconductivity in a graphene grain boundary imageSchematic illustration of the interplay of magnetism and superconductivity in a graphene grain boundary, a potential building block for carbon-based topological qubits Credit: Jose Lado/Aalto University

In the quantum realm, electrons can behave in interesting ways. Magnetism is one of these behaviors that can be seen in everyday life, as is the rarer phenomena of superconductivity. Intriguingly, these two behaviors are often antagonists - the existence of one of them often destroys the other. However, if these two opposite quantum states are forced to coexist artificially, an elusive state called a topological superconductor appears, which is useful for researchers trying to make topological qubits.

Researchers manage to induce “artificial magnetic texture” in graphene

An international research team, led by the University at Buffalo, has reported an advancement that could help give graphene magnetic properties. The researchers describe in their work how they paired a magnet with graphene, and induced what they describe as “artificial magnetic texture” in the nonmagnetic material.

Induced magnetism in graphene could also promote spintronics imageThe image shows eight electrodes around a 20-nanometer-thick magnet (white rectangle) and graphene (white dotted line). Credit: University at Buffalo.

“Independent of each other, graphene and spintronics each possess incredible potential to fundamentally change many aspects of business and society. But if you can blend the two together, the synergistic effects are likely to be something this world hasn’t yet seen,” says lead author Nargess Arabchigavkani, who performed the research as a PhD candidate at UB and is now a postdoctoral research associate at SUNY Polytechnic Institute.